• 한국컴퓨터정보학회논문지
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• 제24권6호
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• pp.73-80
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• 2019

In this paper, we propose an effective dynamic range compression (DRC) method of infrared images. A histogram of infrared images has narrow dynamic range compared to visible images. Hence, it is important to apply the effective DRC algorithm for high performance of an infrared image analysis. The proposed algorithm for high dynamic range divides an infrared image into the overlapped blocks and calculates Shannon's entropy of overlapped blocks. After that, we classify each block according to the value of entropy and apply adaptive histogram modification method each overlapped block. We make an intensity mapping function through result of the adaptive histogram modification method which is using standard-deviation and maximum value of histogram of classified blocks. Lastly, in order to reduce block artifact, we apply hanning window to the overlapped blocks. In experimental result, the proposed method showed better performance of dynamic range compression compared to previous algorithms.

• 전기전자학회논문지
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• 제22권4호
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• pp.907-915
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• 2018

본 논문에서는 저가형 적외선 거리 센서의 성능을 개선하는 방법을 제안한다. 적외선 거리 센서는 반사광의 강도를 측정하여 거리로 환산한다. 제안하는 방법은 센서의 감지 거리를 개선하고 다양한 조명환경에서도 강인하게 동작하도록 한다. 이는 센서의 특성곡선을 추출하고 이를 바탕으로 HDR(High Dynamic Range) 기법을 적용함으로써 가능해졌다. 적외선 입력의 세기와 노출 시간을 다양하게 변화시켜서 센서의 출력값을 획득하였고 이로부터 센서의 특성곡선을 추출하였다.

• 한국컴퓨터정보학회논문지
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• 제22권7호
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• pp.39-45
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• 2017

In this paper, we propose three compensation methods to solve problems in high-resolution airborne infrared camera and to improve long-range target information acquisition performance. First, image motion and temporal noise reduction technique which is caused by atmospheric turbulence. Second, thermal blurring image correction technique by imperfect performance of NUC(Non Uniformity Correction) or raising the internal temperature of the camera. Finally, DRC(Dynamic Range Compression) and flicker removing technique of 14bits HDR(High Dynamic Range) infrared image. Through this study, we designed techniques to improve the acquisition performance of long-range target information of high-resolution airborne infrared camera, and compared and analyzed the performance improvement result with implemented images.

• 한국염색가공학회지
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• 제17권4호
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• pp.7-14
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• 2005

The purpose of this study was to develop the color matching program with the excellent camouflage capacity in the near infrared range($\~$1100nm) including the visible light range for cotton fabrics. It was measured IR spectral reflectance in the range of $380\~1,100nm$ after dyed with vat dyes, and we made database for reflectance with various concentration on vat dyes which have a low reflectance value in the infrared range. The color matching algorithm that could be simulated in both the human visible light and the near infrared range was constructed by numerical analysis method using the database. In this study we also developed the dyeing conditions and dyeing process through the continuous-dyeing experiment with the vat dyes for cotton fabrics.

• Journal of the Korean Physical Society
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• 제73권12호
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• pp.1821-1826
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• 2018

Uniformity is a key feature of state-of-the-art infrared focal planed array (IRFPA) and infrared imaging system. Unlike traditional infrared telescope facility, a ground-based infrared radiant characteristics measurement system with an IRFPA not only provides a series of high signal-to-noise ratio (SNR) infrared image but also ensures the validity of radiant measurement data. Normally, a long integration time tends to produce a high SNR infrared image for infrared radiant characteristics radiometry system. In view of the variability of and uncertainty in the measured target's energy, the operation of switching the integration time and attenuators usually guarantees the guality of the infrared radiation measurement data obtainted during the infrared radiant characteristics radiometry process. Non-uniformity correction (NUC) coefficients in a given integration time are often applied to a specified integration time. If the integration time is switched, the SNR for the infrared imaging will degenerate rapidly. Considering the effect of the SNR for the infrared image and the infrared radiant characteristics radiometry above, we propose a-wide-dynamic-range NUC algorithm. In addition, this essasy derives and establishes the mathematical modal of the algorithm in detail. Then, we conduct verification experiments by using a ground-based MWIR(Mid-wave Infared) radiant characteristics radiometry system with an Ø400 mm aperture. The experimental results obtained using the proposed algorithm and the traditional algorithm for different integration time are compared. The statistical data shows that the average non-uniformity for the proposed algorithm decreased from 0.77% to 0.21% at 2.5 ms and from 1.33% to 0.26% at 5.5 ms. The testing results demonstrate that the usage of suggested algorithm can improve infrared imaging quality and radiation measurement accuracy.

• The Journal of Korean Physical Therapy
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• 제31권1호
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• pp.56-61
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• 2019

Purpose: The spasticity of stroke patients decreases the ankle range of motion and increases the gastrocnemius muscle tone. This study examined the effects of stretching exercise and far infrared irradiation on the ankle function in stroke patients with spasticity. Methods: This study was conducted on 20 stroke patients admitted to Jesaeng General Hospital, who were divided into a study group (stretching exercise with far infrared) and control group (stretching exercise only). The dorsiflexion range of motion was measured using a smartphone and the medial gastrocnemius muscle tone and stiffness were measured using a Myoton pro. Results: With the exception of the non-paretic gastrocnemius muscle tone in the control group, the medial gastrocnemius muscle tone and stiffness decreased significantly in both groups. In both groups, the dorsiflexion range of motion increased significantly. In addition, the experimental group had a significantly higher dorsiflexion range of motion than the control group. On the other hand, there was no significant difference between the two groups in terms of the medial gastrocnemius muscle tone and stiffness. Conclusion: For stroke patients with spasticity, stretching exercises increased the ankle's range of motion and decreased the gastrocnemius muscle tone. The addition of heat therapy further increased the ankle's range of motion. On the other hand, as the sample size was small, future studies should include more subjects.

• 제어로봇시스템학회논문지
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• 제14권10호
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• pp.1005-1013
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• 2008

This paper describes a new sensor system for 3D range measurement using the structured infrared light. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and the projected infrared light are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Identification of the cells from the pattern is the key issue in the proposed method. Several methods of correctly identifying the cells are discussed and verified with experiments.

• Journal of Advanced Marine Engineering and Technology
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• 제29권5호
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• pp.560-570
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• 2005

In this paper, we discuss the tracking system for a wheelchair which can follow the path of a human target such as a nurse in hospital. The problem of human tracking is that it requires recognition of feature as well as the tracking of human positions. For this purpose the use of a high cost visual sensor such as laser finder or streo camera makes the tracking a high cost additional expense. This paper proposes the tracking system uses a low cost infrared range-finder and CCD camera, The Infrared range-finder and CCD camera can create a target candidate through each target recognition algorithm. and this information is fused in order to reduce the uncertainties of a target decision and correct the positional error of the human. The effectiveness of the proposed system is verified through experiments.

• Journal of Advanced Marine Engineering and Technology
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• 제27권5호
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• pp.641-647
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• 2003

The use of infrared range-finder sensor as the environment recognition system for mobile robot have the advantage of low sensing cost compared with the use of other vision sensor such as laser finder CCD camera. However, it is not easy to find the previous works on the use of infrared range-finder sensor for a mobile robot because of the non-linear characteristic of that. This paper describes the error due to non-linearity of a sensor and the correction of it using neural network. The neural network consists of multi-layer perception and Levenberg-Marquardt algorithm is applied to learning it. The effectiveness of the proposed algorithm is verified from experiment.

• 제어로봇시스템학회논문지
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• 제15권5호
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• pp.519-524
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• 2009

This paper describes a new sensor system for 3D environment perception using stereo structured infrared light sources and a camera. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and two projected infrared light sources are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Two successive captures of the image with left and right infrared light projection provide several benefits, which include wider area of depth measurement, higher spatial resolution and the visibility perception.